The present invention relates to the construction of vehicular transmissions and in particular to the construction of a gear box for shifting the transmissions of motorcycles and similar small vehicles.
As is known, the transmission for motorcycles and similar vehicles comprises a set of gears arranged so as to be shiftable into cooperative engagement with each other to provide a variety of transmission speeds. The shifting of the gears is accomplished through the operation of a plurality of selector or shift forks which are actuable in unison by a shift gate which is manually movable by the gear lever. The gate in general, is a flat plate in which is provided a groove associated with each of the selector forks and in which the fork actuating pin is received. On movement of the plate each of the selector forks is shifted a predetermined or selected distance to obtain a combination of gear engagement as desired. Until now the movement of the shift gate in its horizontal plane and in its straight angular or rectangular direction has been controlled by holding the gate at its top and bottom and by guiding it in retaining rails or the like engaging each of the opposite flank edges. This arrangement requires a high degree of precision in forming and cutting all of the guiding surfaces and grooves. This precision was not always possible and in most cases it was necessary to compensate for the variance in manufacturing tolerances by the use of complex and expensive means merely to ensure the proper movement of the gate.
It is the object of the present invention to provide a gear box construction of the type described which overcomes the disadvantages of the known prior art.
It is a further object of the present invention to provide a gear box construction of the type described which is simple, inexpensive, easily manufactured and repaired.
It is a further object of the present invention to provide a gear box construction of the type described in which manufacturing accuracy and precision of construction is obtained with simple methods and at a low expense.
It is a further object of the present invention to provide a gear box construction of the type described having a smaller number of assembly relationships requiring precise tolerance, the result of which is a greater shifting accuracy.
It is a further object of the present invention to provide a gear box construction of the type described in which the gate may be precisely indexed and positioned in its several shift positions and wherein the gate is easily and simply locked in such position.
The foregoing objects, other objects, and numerous advantages will be apparent from the following disclosure of the present invention.